UST GS: Fast Compost Making with Wild Sunflower

Dr Abe V Rotor
Living with Nature - School on Blog
Paaralang Bayan sa Himpapawid (People's School-on-Air) with Ms Melly C Tenorio; 738 DZRB AM, 8-9 evening class Monday to Friday

Wild sunflower, Tithonia diversifolia may have been introduced into the Philippines from Mexico by the Spaniards.

 Who would have thought that those shrubs with bright yellow flowers growing by the roadsides or wastelands make excellent organic fertilizer?

entomology 

      Wild sunflower, Tithonia diversifolia, has been found to contain high levels of nitrogen content, exceeding nearly six percent. It has enzymes that hasten decomposition and cut down composting time from three months to just a few weeks. This is why it is an excellent additive for composting rice hay and other farm wastes, materials which have low nitrogen contents, decomposition.

      Sunflower added to compost piles builds heat and sustains it at a high level of over 55 degrees Celsius. At this temperature weed seeds and harmful microorganisms are killed, including those that cause acidic reactions.  Acidic soil “locks up” nutrients that are otherwise made available for plant use.

      With the addition of chopped sunflower into the compost pile, its pH value remains at seven to eight pH (neutral to slightly alkaline), throughout the decomposition period.  Under this condition nitrogenous materials are immediately mineralized into ammonium nitrogen (NH₄N+) and nitrate (NO₃) which are directly absorbed by the plants.

      These are highlights of a graduate research study by Prof. Luisito Evangelista at the University of Santo Tomas for a masteral degree in biological science.  “Accelerated composting is the key to successful production of on-farm organic fertilizer, specially in areas where sunflower abounds,” Evangelista claims. 

      In areas where the inoculant is not available, sunflower is an alternative to Trichoderma a cellulose-acting fungus strain developed by Dr. Virginia C. Cuevas of the Institute of Biological Sciences at UPLB.  

      When the sunflower-activated compost was used on Red Creole onions, yield increased by as much as 20 percent, while the physical quality of the bulbs improved.  Other than being bigger, the bulbs are brighter, heavier and more uniform in size. Their necks are well closed, reducing the danger of rotting during storage.

      Here are ways to make sunflower compost:

1.  Prepare a well-drained area, half shaded if possible.  Here, construct a compost pile of 2 x 4 meters in dimension, and breast high when compacted.

2.  Prepare the raw compost materials by chopping the rice straw and green wild sunflower separately.  The ratio by weight of sunflower to rice hay is 3:1.  Ready chicken droppings (or animal manure) and topsoil from the farm.

3.  Pile these materials in the following arrangement: the rice hay makes the first layer, 20 cm thick.  On top of layers are the chopped sunflower, followed by manure and soil.

4.  Make a second set of layers on top of the first, compacting the pile as the process is repeated. The pile should not be higher than 1.5 meters for convenience in watering and turning over.

5. Vertically insert aeration tubes made of bamboo poles onto the pile 50 cm apart. The tubes are made by partly opening the nodes, outside and inside to allow air to enter and for heat to rise.

6.     Monitor temperature with a thermometer inserted through the tubes.

Heat is expected to increase immediately, reaching its peak within two weeks before it declining.

7.  Maintain watering sufficient to keep moisture content at 60 to 70 percent.  Use plastic or burlap sacks to cover the pile, protect it from rain, and help conserve the heat generated.

8.  As decomposition progresses, the pile will shrink and the temperature will soon equal that of the surroundings. After three to four weeks, the compost is “ripe” for harvesting.  To facilitate the process, turn the pile once or twice  before reaping.

    

To know if the compost can now be used, here are the indicators:
· Make sure there is no foul odor emitting from the pile.
· The temperature must have dropped and is about the same as that of the surrounding area.
· The original substrates are no longer recognizable.
· The color is dark, loamy and soft to the touch.

     Composting is a bio-oxidative process, which results in the production of a stable organic product, contributing directly to soil conditioning and fertility. In many books, it is called mineralization, or the breaking down of organic compounds into their elemental forms and as they settle down in the soil. This process is particularly true with nitrogen. This is nature’s way of recycling chemical compounds, from organic to inorganic form, and vice versa.

      Composting rice hay alone is not advisable as it has a low C:N ratio.  This is the reason why farmers seldom convert rice hay (or corn stover) into compost. They would rather use rice hay roughage, or kindling for fine.

      In terms of dry weight, rice hay contains very low nutrients - 0.86 percent Nitrogen, 45.91 total Carbon, 0.16 Phosphorus, 2.84 Potassium.  Compare this with the analysis of dry farm manure (carabao): 1.02 N, 10.66 C, 5.33 P and 1.92 K, whereas dried wild sunflower contains 5.53 N, 55.83 C, 0.36 P, and 2.78 K.  Soil on the other hand contains 0.13 N, 1.49 C, 28.36 P and 0,01 K.

      It is clear that the incorporation of topsoil, manure and wild sunflower in the compost pile will boost nitrogen (N), carbon (C), Phosphorous (P) and Potassium (K) elements therefore, increasing the nutrient value of the finished compost.

      This means that the C:N becomes closer to 30:40 the more valuable a compost it becomes, while the rate of decomposition is accelerated. By maintaining moisture content at 60 to 70 percent and temperature at 50 degrees centigrade in the initial two weeks, the pH level stabilizes at 6 to 8pH.  This is favorable to the development of biological and chemical reactions.  

      Composting then, basically, is following nature’s formula.  In nature, crop residues are left on the field after harvest and allowed to decompose or be eaten up by animals, was likewise leave their dropping on the ground. In both cases, the end products become part of soil together with weeds and other plants that are normally incorporated during plowing. This may be augmented by green manuring, the planting of leguminous plants like Indigo (Indigofera hirsuta L) which is purposely incorporated into the soil before the planting season.

      This system traditional practice, holds the key to sustainable productivity of centuries-old farmlands. It is also common in agricultural societies throughout the world, having evolved naturally. Traditional farming, after all, is a shared experience with man living in harmony with nature.  What type of judgment can man give to modern agriculture which uses synthetic inputs, offering high production outputs, but leaving the farms despoiled in the process?    

      Perhaps we should turn our attention to another example of natural composting.  The floor of a forest is continuously being built by composting.  It is a living carpet inhabited by a complex population of organisms responsible for converting organic materials into inorganic and elemental forms. These are then recycled, down to the succeeding generations of organisms.

 Closeup of the flowering plant  

      Natural composting is also observed in insect eating plants like the pitcher plant and the sundew.  It is demonstrated in the watery axils of bromeliads (tropical American herbaceous plants like pineapple or Spanish moss), which trap water and dirt. This mini pool is home to wrigglers, frogs, fish and reptiles. It is no wonder how bromeliads can live an epiphytic (living on the surface of plants) existence without reaching the soil for subsistence.

      The ant plant is another example.  Its bulbous rhizome (causing to take root) is filled with a colony of ants that “eat” through a complex tunnel network.  The inside is a laboratory which produces organic materials that the plant uses for its growth.  This is a classical example of symbiosis.

 

      Next time you find wild sunflowers growing where a lot of farm residues are available but wasted, think of the potential organic fertilizer that can be produced. It is the key to natural and environment friendly farming.  In nature, nothing is wasted. ~